[Xorp-hackers] Potential null pointer dereference.

[Pavlin Radoslavov]

Ben Greear <greearb at candelatech.com> wrote:

> Ben Greear wrote:
> > While merging my old patch set with the latest xorp tree, I believe
> > I found a potential null pointer dereference.  Here is my attempt
> > at fixing it:
> > 
> > [greearb at file-server control_socket]$ cvs diff -u netlink_socket_utilities.cc
> > Index: netlink_socket_utilities.cc
> > ===================================================================
> > RCS file: /cvs/xorp/fea/data_plane/control_socket/netlink_socket_utilities.cc,v
> > retrieving revision 1.12
> > diff -u -r1.12 netlink_socket_utilities.cc
> > --- netlink_socket_utilities.cc 8 Jan 2008 23:30:09 -0000       1.12
> > +++ netlink_socket_utilities.cc 26 Feb 2008 19:40:36 -0000
> > @@ -332,9 +332,10 @@
> >          const IfTreeVif* vifp = iftree.find_vif(if_index);
> >          if (vifp == NULL) {
> >              if (! is_deleted) {
> > -               XLOG_FATAL("Could not find interface and vif for index %d",
> > +               XLOG_ERROR("Could not find interface and vif for index %d",
> >                             if_index);
> >              }
> > +           return XORP_ERROR;
> >          }
> >          if_name = vifp->ifname();
> >          vif_name = vifp->vifname();
> > 
> 
> 
> Here's another one:
> [greearb at file-server ifconfig]$ cvs diff -u ifconfig_parse_netlink_socket.cc
> Index: ifconfig_parse_netlink_socket.cc
> ===================================================================
> RCS file: /cvs/xorp/fea/data_plane/ifconfig/ifconfig_parse_netlink_socket.cc,v
> retrieving revision 1.17
> diff -u -r1.17 ifconfig_parse_netlink_socket.cc
> --- ifconfig_parse_netlink_socket.cc    21 Feb 2008 02:02:33 -0000      1.17
> +++ ifconfig_parse_netlink_socket.cc    26 Feb 2008 20:06:18 -0000
> @@ -603,7 +603,8 @@
>              //
>              return;
>          }
> -       XLOG_FATAL("Could not find vif with index %u in IfTree", if_index);
> +       XLOG_ERROR("Could not find vif with index %u in IfTree", if_index);
> +        return;
>       }
>       debug_msg("Address event on interface %s vif %s with interface index %u\n",
>                vifp->ifname().c_str(), vifp->vifname().c_str(),
> 

Ben,

Did you see those FATAL/ERROR statements actually triggered when
running XORP?
The reason those XLOG statements are FATAL is to capture bugs that
might be hiding somewhere else.
If you were able to trigger those statements, could you provide
instructions how to reproduce the problem so we can investigate it.

Thanks,
Pavlin